Dynamo-electric machine



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DYNAMO ELYEGTRIG MACHINE.

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(NO MOdeL) 2 Sheets-Sheet 2.

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, DYNAMO ELECTRIC MACHINE.

No. 379,284. Patented Mar. 13, 1888.

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fi JMw UNITED STATES PATENT OF I E.

LEWIS 0. RICE, OF DENVER, COLORADO.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 379,284, dated March13, 1888.

Application tiled July 1, 1887. Serial No. 243,098.

To all whom, it may concern.-

Be it known that I, Lewis 0. RICE, a citizen of the United States, and aresident of Denver, in the county of Arapahoe and State of 0010- rado,have invented certain new and useful Improvements in Dynamo-ElectricMachines;

. and I do hereby declarcthat the following is a full, clear, and exactdescription of my invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention, which is applicable both to dynamoelectric machines and toelectric motors, consists in making both the field-magnet and thearmature in a ring form,with Pacinotti projections from the core betweenthe bobbins. These rings are placed one within the other, the inside onehaving external projections and the outside one having correspondinginternal projections. These rings are made up of annular disks placedside by side,with an ample spacing between them for ventilation. Theventilating-spaces in the field-magnet and armature, respectively, areradially in line with each other, so that a current of air can pass fromthe center outward through both. Either the internal or the externalring can be held stationary, while the other is made to rotate in theusual manner. Both rings are Wound with the same number of bobbins,which are connected in a closed series, as in the ordinary Gramme orPacinotti winding. The bobbins of one ring are connected to the ordinarycom mutator or collector, upon which bear the usual sliding brushes,while the bobbins of the other ring are similarly connected to astationary series of contact-points, and switches are made to bear adjustably upon these points, so that the connection may be varied at willand the magnetism of the ring correspondingly shifted.

In the accompanying drawings, Figure 1 is an end elevation of the coresof the two rings. Fig. 2 is a side elevation, partly in section, of theoutside ring; and Figs. 3, 4, and5illustrate the electrical connections.

As shown in Figs. 1 and 2, the outer ring is made up of a series ofannular disks, B B, 850., placed side by side in such number that thering becomes cylindrical in form. These disks are held in place by bolts0, parallel with the (No model.)

axis, and washers E, placed on the bolt between each pair of disks,separate them a sufficicnt distance to permit of ample ventilation. Thering is fastened to end hubs or spiders, D, in a well-known manner. Theinner ring is made up in the same manner, being smallerin size ordiameter, so as to be capable of rotating freely within the outer. one..The Paci notti projections on the internal ring extend outwardly, whilethose on the external ring extend inwardly. The air-spacing on the innor ring corresponds with that on the outer ring, so that thecirculation may be direct radially. The cores of the two rings are madeequal in cross-section, so that there is a complete magneticsatisfaction between armature and field and no preponderance of fieldover the armature, as is usually the case. Each ring has a bobbin woundon it between each pair of projections. These bobbins are connectcd in aclosed series, as is usual in the Gramme or Pacinotti winding. On theinner ring a wire is led from a point between each pair of bobbins to aninsulated plate or commutator, G, upon which the brushes K and K bear atdiametrically-opposite points. The winding on the outsidering is thesame;butthe wires from between the bobbins lead to a series ofstationary contact-points, M, upon opposite points of which bear,respectively, the two switches N and N, through which the current isadmitted to the coils. The two switches N and J. are independentlyadjustable, so that the polar points need not be exactly diametricallyopposite, but at any point desired for regulation or adjustment of themachine. As is well known, the current entering each ring will dividebetween the two halves of the ring, and create in the core consequentpoles where the current enters and leaves the coils, respectively. Inthe outer ring the polar points can be shifted around the ringcircumferentially by means of the switches N and N, which determine thepoints of ingress and egress for the current, and when this ring is usedas the field-magnet for the inner ring as an armature the shifting ofthe switches may take the place of the shifting of the brushesK and K,which is the present method of adjustment. This arrangement permits asimple and easy regulation of the motor or generator,-either by hand orautomatically, as well as a means of adjustment to prevent abnormalsparking at the coinmutator-brushes. The outer ring can be in eitherserial or shunt relation to the inner ring.

In Fig. 3 the current passes directly from the brushes K and K,respectively, to the switches N and N, which form the terminals of themachine, while a shunt passes from N through the outer ring and back toN.

In Fig. 5 the current from K passes to N, and thence through the outerring to N, the terminals being in this case N and K, while the two ringsare in series.

Fig. 4 is a diagram of the circuits in the outer ring, and willbereadily understood from the description already given.

What I claim is \Vilanesses:

J. It. HOMER, H. R. Grass.

